It is a common problem for a nail to bend when being driven into hard material, such as very hard wood, a knot in a board, or brittle materials like plaster. Due to cost, and the hazards of fracture with stronger but more brittle material, nails are made of mild steel. They are suited only for moderately resistive materials, and often will buckle and bend under a hammer blow when the impact is not truly axially absorbed by the driving of the nail into the surface or, variations in the material density is encountered by the nail point.
Once a nail bends, it is generally deemed useless and discarded. Often, attempts are made to salvage a nail that has become bent prior to being fully driven, by striking its shank from the side or even by removing it with the hammer's claw and striking upon a firm surface to restraighten the nail shank. In the latter instance, the nail is thereafter reinserted into the workpiece and driven in by the hammer. In any case, these prior efforts are time consuming and thus wasteful of both hammering time and material. Thus, a device is needed which will allow a bent nail to be driven the remainder of the distance into a wooden or other composition of material.